Field olfactometry is the use of a technique or device to measure odor in ambient air by a single individual. Field olfactometry can be used to detect levels of odor in ambient air near industrial, agricultural, and municipal operation sites, such as facilities for wastewater treatment, landfills, composting, and manufacturing. Many governmental bodies require that the level of odor in the air surrounding such sites conform to various regulatory guidelines to reduce the impact on the general public.